The present invention relates to a high-volume, postcollation copy engine or duplicator system in which system control is provided to coordinate and integrate duplicator and large capacity sorter operations for efficient, low cost and flexible operation of the reproduction process.
There are a variety of commercial applications of reproduction technology where a need exists to reproduce manuals or books, or sets thereof, containing up to thousands of pages that are suitably assembled such as in three-ring binders or in bound units. A large number of book copies may be required for distribution to users or customers. Applications like these are called high-volume applications.
In particular high-volume applications, the books may have to be revised or updated periodically, such as every three or six months. In the revision process, some but normally not all pages will be modified and some pages may be deleted or added. In many cases, trade practices or regulatory requirements may make it necessary to reproduce the entire revised book or set of books as opposed to reproducing insert pages for appropriate placement in the original book copies. In any case, the page insert approach is typically undesirable because it is labor intensive and because of the likelihood of assembly errors.
The original text, graphics, and photographs, that constitute the book content, may reside in multiple sources. For example, an original may reside on microfilm, in electronic storage, on standard 81/2".times.11" paper, or on "paste-ups". Originals from which reproductions are to be made are derived from the multiple storage sources and placed on one or more selected media.
A typical commercial application in which high-volume reproduction technology is needed is that in which a manufacturer makes and sells relatively complex products for which maintenance books must be issued and revised from time to time. The production of maintenance books for a product which may be supplied in a variety of forms or models typically is relatively complex because of book differences that are required for different models and/or customers.
Offset lithography is one process that has often been used for high-volume reproduction, but it is typically relatively expensive. In this process, extensive setup time is required for building each master original or revised original. Relatively high pressman labor operating costs are incurred, and up to 10% of the total copy output constitutes waste copies caused by process adjustment during job startup and shutdown. It is noteworthy, however, that offset lithography does in general provide high resolution production of photographic originals.
Large output sorters, having multiple towers containing up to 600 or more bins, have been employed in offset lithography to support post-collation book production for high-volume jobs. However, the operation of such sorters and the lithography production process as a whole has been relatively inflexible especially in terms of accommodating more complex jobs that involve varying production requirements within a particular job or from job to job. Such inflexibility stems from the very nature of the whole lithographic reproduction and sorting process along with an absence of process controls that, if implementable at all, could otherwise facilitate the creation of added process flexibility.
In high-volume jobs that require "limitless" sorting, that is, a number of copies greater than the machine reproduction capacity, typically the operator of the lithography process must determine the job breakup and run the job parts accordingly. Another example of relative inflexibility in the offset lithography process is that in which some book copies may require certain pages to be different from corresponding pages in other book copies. While the lithography process may be operated to permit collation of the proper page copies in the various book copies, such process operation is highly inefficient, costly and inconvenient.
An additional example of flexibility limits in the offset lithography process is that in which a capability is needed for job parking at the end of work shifts. A job is parked when work is left in sorter bins at the end of a shift and the job is picked up again on the next shift, often the next day. The lithography pressman has limited system hardware support in resuming the parked job and completing it.
Pre-collation copying with use of a duplicator is another process that has been used for reproducing multiple copies of original manuals or books. However, the machine capacity limits successive segment sizes which therefore must be "hand-married" or manually collated after production. Copy integrity is also a problem in the pre-collation reproduction process. Thus, an occasional skewing of an original document on the platen glass requires inspection of all output copies to uncover any skewed ones and thereby assure copy product quality. Such inspection is impractical for high-volume jobs.
Another process that lends itself to high-volume reproduction is a process in which post-collation copying is performed with use of a duplicator and a high capacity sorter. Generally, the availability of electronic control with a duplicator provides a basic capability for creating process flexibility in high-volume reproduction jobs.
As compared to a pre-collation duplicator process, a postcollation duplicator process facilitates the performance of highly complex jobs because the layout of collation bins allows for the tailoring of some book copies to meet the requirements of particular customers or particular product models. Moreover, possible future commercial use of a common electronic format for source originals could be efficiently implemented in high-volume reproduction jobs with the use of electronically controlled duplicators.
High-volume, post-collation duplicators have been generally unavailable commercially because of a lack of required technology development.
More specifically, in a conventional duplicator having a sorter, the requested quantity of copies of successive originals are normally distributed sequentially in the sorter bins. Sorter return to the starting bin occurs only after that bin has been emptied. In the uncollated duplex mode of a high-volume duplicator, this conventional procedure results in a copy output distribution that can be very confusing to the operator of the duplicator.
As an illustration, in a duplicator having a duplex tray with a 100 sheet capacity, the duplicator is limited to making 100 duplex copies of an original or original pair before moving to the next original or original pair. If the requested copy quantity is 1000, for example, 100 copies of original 1/2 would be sent to the first bin or set of bins (either of which corresponds to a logical bin), 100 copies of original 3/4 would be sent to the next logical bin, and 100 copies of each successive original would be sent to successive logical bins in sequence until all of the originals have been processed.
Since 1000 copies are needed for each original, the originals are again copied to place 100 copies of each in succession in the next set of logical bins corresponding in number to the number N of originals. This process is repeated eight additional times to produce the requested copy quantity of 1000 for each original.
As a result, 100 copies of original 1/2 are located in the first logical bin, 100 copies of original 3/4 are located in the second logical bin, etc. through the Nth logical bin where the 100 copies of the Nth copy are sent. The 1000 copy stack of each successive original is thus broken into ten 100 copy stacks which are separated by stacks of 100 copies of other originals. In high-volume copy work, such output delivery of copies would be confusing to the duplicator operator and therefore is undesirable from a product marketing standpoint.